Some electronic devices may operate in a reduced pressure atmosphere, e.g., a vacuum, or in an inert gas atmosphere. Examples of such devices include infrared sensors, vacuum tubes, and vacuum transistors, which are typically hermetically sealed within glass or metal containers to maintain the desired atmosphere.
Bolometers are one type of infrared sensor that operates in a reduced pressure atmosphere. A bolometer is a detector that changes resistance in response to incident radiant energy. A bolometer can thus be used to measure the amount of heat radiated from an object. An array of bolometers, such as in a focal plane array (FPA), may be used to facilitate infrared imaging.
The array of bolometers can be enclosed within a hermetically sealed container to provide heat isolation. In this manner, sources of heat other than the radiant energy intentionally being measured are mitigated so as to enhance the quality of images provided by the detectors. The array of bolometers is positioned behind a window of the hermetically sealed container to permit communication of the radiant energy thereto.
Although contemporary methods for fabricating hermetically sealed structures for such electronic devices have proven generally suitable for their intended purpose, they do possess inherent deficiencies that tend to detract from their overall desirability. For example, contemporary methods for sealing such containers often involve the use of a pinch tube. The pinch tube is used to evacuate and/or backfill the container. Once the desired atmosphere is established within the container, the pinch tube is pinched off and sealed. Pinching off the tube generally involved crimping the tube closed and cutting the tube at the crimp.
Such sealing via the use of a pinch tube must be accomplished in a manner that tends to maintain the desired atmosphere within the container. There are costs (both labor and materials) associated with performing the pinching process and there is also a failure rate (such as due to subsequent leakage of the pinch tube) associated therewith. Consequently, it is desirable to provide a less costly and more reliable process for evacuating, backfilling, and/or sealing such containers.